1. Field of the Invention
The present invention relates to a videophone terminal that can convey the emotions and impressions of a user so they can be easily understood by a co-communicant.
2. Description of the Related Art
In a videophone system constituted by a plurality of videophone terminals and a network, a picture obtained by a videophone terminal is transmitted, with speech, to the terminal of a co-communicant across a network. Therefore, while a user is conversing with a co-communicant at a remote location, the user can simultaneously watch the face of the co-communicant. And since the two can see and hear each other during their conversation, not only is the tone of voice of a co-communicant transmitted but also his or her appearance is presented visually, a more realistic and higher-level communication process can be performed.
However, since some users do not want their pictures transmitted to their co-communicants' terminals and others do not think that conversing while viewing pictures of themselves or their co-communicants is amusing, another technique has been developed whereby the feature points of individual facial features, such as eyebrows, eyes, the nose and the mouth, are extracted from a picture of a user, and based on the feature points, a virtual character that resembles the face of the user is generated and is transmitted as the personality of the user to the terminal of a co-communicant (Patent document 1: JP-A-2002-511617; and Patent document 2: JP-A-2002-511620).
According to this technique, first, a picture of a user's face (hereinafter referred to as a “face picture”) is examined to identify the area that corresponds to the face of the user, and points (hereinafter referred to as “feature points”) representing individual facial features, such as the eyebrows, the eyes, the nose and the mouth, are extracted from the face picture, as indicated in FIG. 1 for explaining a face picture and the individual feature points. Then, in accordance with the feature points, a virtual character resembling the face of the user is generated based on the an average face obtained by averaging the individual facial features. More specifically, differences between the extracted feature points and the feature points for an average face are calculated, the differential data are reflected on the average face, and a virtual character resembling the face of the user is generated. In FIG. 2, a virtual character that resembles the face of a user is presented.
Next, the movements of the individual feature points on the face picture of the user are tracked and are reflected on the virtual character. In this manner, since the movement of each facial feature associated with a change in the facial expression of the user interacts with the movement of each facial feature of the virtual character, the facial expression of the virtual character changes in consonance with a change in the user's facial expression. The virtual character, however, need not always resemble the face of the user, and when the movements of the feature points in the face picture of the user are reflected on a completely different virtual character, the facial expression of the virtual character may be varied as the facial expression of the user changes.
Furthermore, when all the facial features are moved in the same direction along the coordinate axis of the face picture, it can be assumed that the entire face has been moved. Therefore, any movement by the user, such as the nodding, tilting or shaking of the user's head, can be reflected on the virtual character.
As is described above, according to the conventional technique, since the movements of individual facial features associated with a change in the expression of the user interact with the movements of the facial features for the virtual character, the expression of the virtual character is changed in consonance with the expression of the user. Further, since any movement of the user's head is reflected on the virtual character, the virtual character moves the same as does the user's head while being nodded, tilted or shaken.
The conventional technique, however, merely provides for the direct reflection on a virtual character of changes in a user's facial expression and movements of the user's head, and emotions or impressions that are not accompanied by speech can not be expressed by using the facial expressions and movements of a virtual character. To transmit the emotions and impressions of the user so that they can be easily understood by a co-communicant, therefore, exaggerating changes in the user's facial expression or using representative symbols is better than merely having the virtual character directly reflect changes in the facial expression of the user. Furthermore, since the facial expressions or movements of the virtual character are more amusing by this method, the entertainment value of this method is superior.